Sulfoxide detergent compounds



United States Patent a corporation of Ohio No Drawing. Filed Nov. 14,1962, Ser. No. 237,715

5 Claims. (Cl. 260-607) This invention relates to novel1,1-bis-sulfoxides and detergent compositions containing them.

In constant improvement of organic detergent compounds certain featureshave been found to be highly desirable. These features includeresistance toward the ingredients imparting hardness to water and a highdegree of detergency. Although there are a number of organic detergentcompounds which have these characteristics, detergent compounds havingadditional desirable characteristics find a wider scope of application.

US. Patent 2,658,038, Wayne A. Proell, describes a class of1,2-bis-sulfoxide detergent compounds which are relatively mild to theskin and which have elfective detergency characteristics. These1,2-bis-sulfoxides have the formula.

where R is a lower alkyl, R is an alkyl containing 6 to 20 carbon atomsand R" is H or lower alkyl. Attempts to formulate these1,2-bis-sulfoxide compounds into detergen compositions containingalkaline builder materials (for the purpose of enhancing the detergencyof the 1,2- bis-sulfoxide detergent compounds) showed that the 1,2-bis-sulfoxides are subject to decomposition in the presence of suchalkaline materials. Apparently, the presence of an alkaline materialcatalyzes the decomposition of a 1,2-bis-sulfoxide into odoriferousproducts (e.g., methyl disulfide), thereby reducing the effective amountof detergent and creating a severe odor problem. This decompositionproblem indicated that bis-sulfoxides would generally be unsuitable foralkaline built detergent compositions.

It is an object of this invention to provide novel bissulfoxidedetergent compounds having a high degree of detergency and stability inan alkaline environment. It is a further object of this invention toprovide alkaline built detergent compositions containing suchbis-sulfoxide compounds.

' It was found that these and other objects are achieved in a novelclass of 1,1-bis-sulfoxides having the structure set-forth below and inalkaline detergent compositions containing such compounds, which'have asurprising alkaline stability, as hereinafter more fully described.

wherein R is an alkyl group containing from about 8 to about 16 carbonatoms, preferably in a straight chain, and R and R are alkyl groupscontaining from 1 to 2 carbon atoms. Preferably R and R are methyl.- Theclass of compounds described will hereinafter be referred to more simplyas 1,1-bis-sulfoxides. Examples of the compounds of this invention are:

1,1-bis(methylsulfinyl) nonane 1,1-bis(methylsulfinyl) decane1,1-bis(methylsulfinyl) undecane 1,1-bis(methylsulfinyl) dodecane1,1-bis(methylsulfinyl) tetradecane 3,257,462 Patented June .21, 1966ice 1,1-bis(methylsulfinyl) pentadecane 1,1-bis(methylsulfinyl)hexadecane 1,1-bis(methylsulfinyl) heptadecane 1,1-bis(ethylsulfinyl)tridecane l-(methylsulfinyl)-1-(ethylsulfinyl) tridecane, 1,1-bis-(methylsulfinyl) dodecane, 1,1-bis(methylsulfinyl) tridecane and1,1-bis(methylsulfinyl) tetradecane are preferred compounds of thisinvention because of their 0ptimum detergency characteristics.

In general, the 1,1-bis-sulfoxides of this invention are prepared bysynthetic methods involving the following steps:

' (1) Formation of 1,1-bis(alkylmercapto) alkane by reaction of a loweralkyl mercaptan with a higher alkyl aldehyde;

(2) Oxidation of the 1,1-bis(alkylmercapto) alkane, with H 0 forexample, to form 1,1-bis(alkylsulfinyl) alkane (referred to herein as1,1-bis-sulfoxides).

These steps are illustrated by the following exemplary equations where Ris a C C alkyl group:

An alternative synthesis route can be followed:

1) The preparation of 1,1-bis(alkylmercapto) methane by reacting analkali metal lower alkyl mercaptide with dihalomethane, e.g.,dichloromethane;

(2) The alkylation of the 1,1-bis(alkylmercapto) methane, with a higheralkyl halide for example, in the presence of a strong base, such assodamide, to form 1,1- bis(alkylmercapto) alkane;

(3.) Oxidation of the 1,1-bis(alkylmercapto) alkane, with H O forexample, to form 1,1-bis(alkylsulfinyl) alkane (i.e.,1,1-bis-sulfoxide).

Thesesteps are illustrated by the following exemplary equations whereinR is a C C alkyl group:

CH Cl 2NaSCH CH (SCH +2NaCl In 1,1-bis-sulfoxides of this invention R inthe above general formula can bederived from naturally occurring fatsand oils or from synthetic sources. Mixtures of 1,1- bis-sulfoxides arevery suitable wherein the R groups vary in chain length in the C to Crange, as for example, the alkyl groups from coconut fatty alcohol ordistilled coconut fatty alcohol.

The 1,1-bis-sulfoxides of this invention are useful per se as detergentand surface active compounds. The uses to which surface active compoundscan be put are numerous and well known, e.g., preparing oil-in-wateremulsions, textile treatment, dyeing, flotation, preparation ofrubber'latex, and the like. Desirably the 1,1-bis-sulfoxides are usedwith alkaline builder materials to form built detergent compositions, asfor example, liquid, bar, flake, granular or tabletted granularcompositions. Such compositions have enhanced detergency characteristicsdue to the coaction in aqueous washing solution between the1,1-bis-sulfoxides and the alkaline builder material. It is in such analkaline medium that the surprising and ad vantageous usefulness of the1,1'-bis-sulfoxides, i.e., superior stability in the presence ofalkaline materials, is best demonstrated. Preferably the alkalinebuilder in such detergent compositions is a material selected from theclass consisting of water soluble inorganic alkaline builder salts,water soluble organic alkaline sequestering builder salts and mixturesthereof. Desirably the ratio of 1,1- bis-sulfoxide to the alkalinebuilder material is in the range of about 4:1 to about 1:20. (Parts,ratios and percentages herein are by weight.) Preferably the alkalinevnesium sulfate.

milder material should provide a pH of about 8 to about [1 when thedetergent composition is dissolved in water.

Water-soluble inorganic alkaline builder salts used alone or inadmixtuie are alkali metal carbonates, boates, phosphates,polyphosphates, bicarbonates and silizates. (Ammonium or substitutedammonium builder salts, e.g., triethanolamine, can also be used.)Specific examples of such salts are sodium tripolyphosphate, soiiumcarbonate, potassium carbonate, sodium tetra- )orate, sodiumpyrophosphate, potassium pyrophosphate, sodium bicarbonate, potassiumtriployphosphate, sodium hexametaphosphate, sodium sesquicarbonate,sodium monoand diortho phosphate and potassium bicarbonate. Suchinorganic builder salts enhance the deiergency of the subject1,1-bis-sulfoxides.

Examples of organic alkaline sequestrant builder salts used alone or inadmixture to enhance detergency are alkali metal, ammonium orsubstituted ammonium, aminopolycarboxylates, e.g., sodium and potassiumethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyet-hyl)-ethylenediaminetriacetates, sodium and potassiumnitrilotriacetates and sodium, potassium and triethanolammonium,N-(Z-hydroxyethyl)-nitrilodiacetates. Mixed salts of thesepolycarboxylates are also suitable. The alkali metal salts of phyt-icacid, e. g., sodium phytate are also suitable as organicalkaline-sequestrant builder salts (see U.S. Patent 2,739,942). Alsosuitable are the Water soluble salts ofethane-i-hydroxy-l,l-diphosphonate, e.g., the trisodium and tripotassiumsalts.

The detergent compositions of this invention can contain any of theusual adjuvants, diluents and additives, for example, anionic, nonionic,ampholytic, cationic or zwitterionic detergents, perfumes,anti-tarnishing agents, anti-redeposition agents, bacteriostatic agents,dyes, fluoresers, suds builders, suds depressors, and the like withoutdetracting from the advantageous properties of the composition. Examplesof anionic detergents are sodium-coconut soap, sodium dodecylbenzenesulfonate and potassium tallow alkyl sulfate. Examples of nonionicdetergents are dodecyldimethylamine oxide and the condensation productof coconut fatty alcohol. with 5.5 moles of ethylene oxide. An exampleof zwitterionic detergent is3-(N,N-dimethyl-Nhexadcylammonio)-2-hydroxypropane-l-sulfonate. Anexample of an ampholytic detergent is sodium-3-dodecylaminopropionate.An example of an alkaline-compatible cationic detergent isdodecylmethylbenzyl sulfoxonium methosulfate.

-Following are examples which illustrate the 1,1-bissulfoxide compoundsand compositions of this invention. There are, of course, modificationsof these illustrations which can be made by those skilled in the artwithout departing from the scope of this invention as defined in theappended claims.

EXAMPLE 1 Preparation of 1,1-bis(methylmercapto) dodeccme Lauraldehyde(113 g., 0.62 mole) was dissolved in 500 ml. of benzene and the solutioncooled to C. The mixture was saturated with anhydrous hydrogen chlorideat 0 and methyl mercaptan 108 g. (2.24 moles 80% excess) was bubbled inat 0 C. with stirring of the reaction mixture. Stirring was continuedfor 2 hours at 0 C. following completion of the addition of methylmercaptan, and the mixture was allowed to stand overnight at 0 C.Separation of an aqueous layer occurred 'during the addition andsubsequent standing. The mixture was washed with 50 ml. of waterneutralized with :sodium bicarbonate solution followed by a water wash-.ing. The organic material was dissolved in ether, Washed twice withwater, and the ether solution dried over mag- Following evaporation ofthe ether solwent the residual material was fractionally distilled to a'yield 88.7 g. (55% yield) of 1,1-bis(methylmercapto) dodecane.

Preparation of 1,l-bis(methylsulfinyl) dodecane grams of1,1-bis(methylmercapto) dodecane (0.305 mole) was dissolved in 200 ml.of ethanol, and 69 ml. of 30% hydrogen peroxide (0.67 mole, 10% excess)was added at room temperature with stirring. The mixture was warmed to45 C. for 1 :hour until a monophasic system resulted. Followingovernight standing of the reaction mixture, the solution was cooled to10 C. and filtered. The filter cake was dissolved in refluxing acetoneand recrystallized cooling to 10 C. The 1,1-bis(methylsulfinyl) dodecaneobtained by filtration melted at 62.6- 65 C. and weighed 23.9 g. Furtherprocessing of the mother liquors at lower temperatures afforded recoveryof additional 1,1-bis-sulfoxide. For example, an additional 5 g. ofmaterial substantially identical to the 23.9 g. crop obtained wasobtained by additional chilling to 40 C. Infrared spectra of these cropsshow strong sulfoxide bands at 9.5 microns and no sulfone bands at the7.6 and 8.8 micron positions. Further recrystallization affordsconcentrations of higher melting diastereoisomers (melting points up toC.) without any noticeable change in solution spectra. Analyses on the1,1-bissulfoxide follow: Found: C, 58.3; H, 10.5; 0, 10.2. Calculated:C, 58.4; H, 11.1; 0, 10.4.

1,1-bis(ethy1sulfinyl) dodecane can be prepared in manner analogous tothe process of Example 1 by using a molar equivalent amount ofethylmercaptan instead of methylmercaptan. 1,1bis(methylsulfinyl)tetradecane can be prepared in a manner analogous tothe process of Example -I by using a molar equivalent amount of myristaldehyde instead of lauraldehyde.

EXAMPLE II Preparation of 2,4-dithiapentane Methylmercaptan (96.2 g.,2.0 moles) was added to a solution of 80 g. (2.0 moles) of sodiumhydroxide dissolved in 200 ml. of water and 300 ml. of ethanol Whilekeeping the temperature at 0-10 C. Methylene chloride (84.9 g., 1.0mole) was added to the resulting mercaptide solution at 10-15 C. Themixture was warmed to room temperature and an additional 25 g. ofmethylene chloride was added. The well-stirred mixture was heated to60-70" for 1 hour. The lower layer was then separated and the upperaqueous layer extracted twice with petroleum ether. The petroleum etherextract was combined with the lower organic layer and washed twice withwater and dried over magnesium sulfate. After evaporation of petroleumether the yellow-orange organic residue was distilled through, ahelices-packed column. Fractions boiling up to 146 C. were obtained anddiscarded. The product boiled at 146.5149, yield was 28.8 g. (27%). Theproduct had a very strong mustard-cabbage odor.

Alkylation 0 2,4-dithiapentane To a solution of sodamide in 150 ml. ofliquid ammonia, prepared in the conventional manner from 6.2 g. (0.27 g.atoms) of sodium metal catalyzed by 0.25 g. powdered ferric nitrate, wasadded 2,4-dithiapen-tane (28.8 g., 0.266 mole). The dithiapentane wasadded to the sodamide solution at the reflux temperature of ammonia andwas stirred at the ammonia reflux temperature 1% hours. At the end ofthis period dodecyl bromide (66.2 g., 0.266 mole) was added dropwise tothe stirred mixture. After addition was complete the ammonia was allowedto evaporate oif, and ethyl ether was added as necessary to maintain themixture-liquid stirrable. After allowing the mixture to stand overnight,water was added and the organic layer separated. Following washing ofthe aqueous layer with ether and combining the ether extracts with theetheral solution, the

combined ether extracts were washed twice with an acidic ethanol-watersolution. washed twice with water until neutral and dried over magnesiumsulfate. After removal of the ether the product was fractionated througha Vigreaux column and the fraction boiling at l152l54 C. at 0.75 mm. ofmercury was collected. The yield of the product, 1,1-bis(methylmercapto)tridecane, was 43.1 g. (58.5%). The product had refractive index n=1.4879, d =0.915. Sulfur analyses gave 22.93% sulfur (theory=23.18).

Oxidation of 1,1-bis(methylmercap-t) tridecane To 16.2 g. (0.059 mole)of 1,'1-bis(methy1mercapto) tridecane dissolved in 100 ml. of ethanolwas added slowly, with stirring at room temperature, 6.0 g. (0.176 mole)of 30% aqueous hydrogen peroxide. The mixture was stirred untilhomogeneous and allowed to stand for 48 hours. The ethanol wasevaporated in vacuo after the addition of platinum catalyst to enhanceperoxide decomposition. After the removal of solvents the residue wasdissolved in 400 ml. of hexane and filtered hot through a glass filterpaper to remove catalyst. The filtrate was cooled slowly to roomtemperature, whereupon a crystalline fraction of the desired1,1-bis-sulfoxide separated. This material was harvested by filtration.It melted at 8 8.5-'9 2 C. and weighed 4.6 g. Analyses gave percent C=58.29, percent H='.5 2; percent 0: 10.17 (theory: percent C=58.40;percent -H=11.10; percent 0: 10.37). Further' processing of the motherliquors can be carried out to yield more 1,1-bis-sulfoxidediastereoisomeric mixtures of lower melting point.

Built laundry detergent compositions containing 50% sodiumtripolyphosphate, 30% sodium sulfate and 20% 1,1-bis(n1ethylsul'finyl)tridecane, resulting in lipid soil detergency properties (usingnaturally soiled cloth) superior to like formulations containing sodiumdodecyl benzene sulfonate and approaching like formulations containingsodium tallow alkyl sulfate. The same basic formulation, but containing1,1 bis'(methylsulfinyl) undccane of 1,1-bis(methylsulfinyl) pentadecanehas satisfactory detergent char-acteristics but not as desirable asthose compositions containing the C homolog. As regards detergency,these 1,1-bis-su1foxides in built compositions were about equal to1,2-bis-sulfoxides in built compositions freshly prepared) containing,respectively, the same long chain alkyl groups.

As determined by guinea pig mildness tests, the 1,1- bis-sulfoxides ofthis invention, e.g., 1,1-bis(methylsulfinyl) tridecane, are very mildto the skin. Suoh guinea pig tests are described in Canadian Patent639,398, issued April 3, 1962, to Howard F. Drew et al.

1,1-bis-sulfoxides, e. g., 1,1-bis(methylsul-finyl) tridecane, can beused per se as detergents for hand washing of woolens in aqueoussolution of 1% concentration for example.

To test the alkaline stability of the 1,-1 bis-su1foxides, of thisinvention, particularly as compared to 1,2-bissulfoxides, 8% aqueoussolutions of potassium pyrophos phate were used. A series of samplescontaining 3 grams of 1,1-bis(methylsulrinyl) tridecane in 150 ml. ofthe pyrophosphate solution was compared with a like series of 3 grams of1,2-bis(methylsulfinyl) tetradecane in 150 ml. of the pyrophosphatesolution. (The difierence in one methylene group was found to be notsignificant for purposes of the comparison.) The solutions were kept at60 C. and pH 10. A slow stream of nitrogen was used to sweep volatileproducts into traps containing 3% aqueous mercuric chloride.Periodically the precipitated complex of the methyldisulride withmercuric chloride which formed in the traps was removed, dried andweighed to assess the rates of formation of decompositon products. :In14 days the 1,1-bis-sulfoxide produced no precipitate. The1,2-bis-sulfoxide produced 0.6 gram of precipitate in 1 day, 1.0 gram in5 days and 1.1 grams in 12 days At this point, decomposition of Theetheral extracts were then the 1,2-bis-sulfoxide was substantiallycomplete This demonstrated the suprising alkaline stability of the 1,1-bis-sulfoxide as compared to the 1,2-bis-sulfoxide.

The 1,1-bis-sulfoxides of this invention can be used in efi'ectivealkaline detergent compositions having the following formulations:

GRANULAR DETERGENT Percent 1,1-bis(methylsulfinyl) tride-cane 10 Sodiumdodecylbenzene sulfonate (the dodecyl group being derived fromtetrapropylene) 10 Sodium tripolyphosphate 50 Sodium sulfate 30GRANULAR. DETERGENT Percent 1,l-bis(ethylsulfinyl) tridecane 10Condensation product of one mole of dodecanol and twelve moles of theethylene oxide 3 Sodium pyrophosphate 57 Sodium carbonate 3 Trisodiumphosphate 3 Sodium sulfate 24 LIQUID DETERGENT Percent1,1-bis(methylsulfinyl) undecane 6 Sodium dodecylbenzene sulfonate 6Potassium pyrophosphate 10 Potassium nitrilotriacetate '10 Potassiumtoluene sulfonate 3 Sodium silicate 3.8- Carboxymethyl hydroxyethylcellulose 0.3 Water, balance LIQUID DETERGENT Percent1,1-bis(methylsulfinyl) pentadecane 5 Ethanol 10 Tetrasodiumethylenediaminetetraacetate .10

Water 75 What is claimed is: 1. 1,1-bis-sulfoxide detergent compoundshaving the formula:

References Cited by the Examiner UNITED STATES PATENTS 2,787,595 4/1957Webb 252-138 2,870,216 1/ 1959 Sorensen et al. 260607 3,000,831 9/ 196 1Tuvell 252-138 3,006,962 10/1961 Schultz et al. 260-607 3,006,96310/1961 Buc et al. 260607 3.045,051 7/ 1962 Coma et a1. 260607 3,124,6183/1964 Berry 260--607 OTHER REFERENCES Reid, Organic Chemistry ofBivalent Sulfur, vol. 2,

1960, page 26; and vol. 3, 1960, page 320.

CHARLES B. PARKER, Primary Examiner.

A. T. MEYERS, Examiner.

DELB-ERT R. PHILLIPS, Assistant Examiner.

1. 1,1-BIS-SULFOXIDE DETERGENT COMPOUNDS HAVING THE FORMULA: